Sulfonated 1, 1, 1-trichloro-2,2-bis (p-chlorophenyl) ethane



Patented July 18, 1950 SULFONATED 1 1 ,1-TRICHLORO-2,2-

BIS (p-CHLORPHENYL) ETHANE Ernest Segessemann, Woodridge, N. .l., andNicholas M. Molnar, New York, N. Y.

No Drawing. Application May 17, 1945, Serial No. 594,364

1 Claim.

This invention relates, in general, to insecticidal agents and inparticular to insecticidal agents which can be permanently impregrfitedinto textile fabrics and other goods commonly used in wearing apparelsor house furnishings.

We have discovered that by introducing an auxochrome group into themolecule of 1,1,1- trichloro-2,2-bis (p-chlorophenyl) ethane commonlyknown at DDT the compound can without losing its insecticidal propertiesbe permanently attached onto organic fibres used for instance intextiles, as for example, textile fibres, wool, silk,

cotton, rayon, or the like, or onto fur, feathers,

or the like. In the case of animal fibres, such as wool, silk, feathers,fur, or the like, the compound will fix itself directly to the proteinof the fibre while in the case of vegetable fibres, such as cottonrayon, or the like, permanent impregnation is accomplished with the helpof mordants of the kind that are commonly used in the dyeing ofvegetable fibres.

The fabrics or other goods thus treated are protected against damagefrom vermin such as moths, beetles and other insects and their larvae.The insecticidal effect is permanent and remains after repeated washingor drycleaning of the goods treated.

The term auxochrome group includes the groups or radicals known indyestuff chemistry to possess the property of attaching the dyestuiifirmly to the fibre. Such groups include for instance:

and the like.

A convenient method for imparting an auxochrome group into the moleculeof DDT consists in introducing one or more sulfonic acid groups bytreating DDT with sulfuric acid, chlorosulfonic acid or othersulfonating agents.

Example #1 100 grams of DDT is suspended in 100 grams of chlorosulfonicacid and the mixture is stirred at a temperature of 40 to 50 C. until asample of the reaction mass dissolves clearly in water. Usually areaction time of 3 to 4 hours is required to effect completesulfonation. The product of reaction is then poured into 500 ml. ofwater. Enough caustic soda or sodium carbonate is then added toneutralize the sulfonic acids and any free mineral acids. The productwhich consists of an aqueous solution of the sodium salt of DDT-sulfonic acids, sodium chloride and sodium sulfate may be used directlyin its crude form for 2 the impregnation of textile fibres, fur,feathers, or the like, or it may be concentrated or evaporated todryness or it may be freed from its inorganic impurities prior to itsapplication to textile fibres.

Example #2 60 ml. of the crude aqueous solution obtained in Example #1were diluted to 100 ml. with water. To this solution was then added 5grams of sodium sulfate and 3 ml. of glacial acetic acid. The solutionwas then heated to 40 C. and a piece of knitted wool weighing 15' gramswas introduced. The temperature was then gradually raised at such a ratethat it came to a boil after'ZG minutes. The bath was then kept boilingfor one hour. 1.5 ml. of sulfuric acid was then added and boiling wascontinued for an additional 30 minutes. The wool was then rinsedthoroughly with fresh water and dried.

The treated wool was then exposed to the larvae of moths and of theblack carpet beetle for three weeks without being attacked by thevermin; while untreated pieces of wool used as controls were freely fedupon by the larvae. The exposure tests were repeated after the piece oftreated wool had been washed six times. Again the wool remainedunattacked by the vermin.

The piece of treated wool was then put through a drycleaning processusing Stoddard solvent and a commercial dry-cleaning soap. Tests on thelarvae of moths and black carpet beetle were again negative indicatingthat the fabric had retained its insecticidal or insect repellentquality.

Example #3 20 grams of DDT was suspended in 25 grams of Oleum containing20% free S03 and stirred at C. for 5 hours. The reaction mixture waspoured into 300 ml. of water and neutralized with caustic soda. Thesolution was then filtered ofi from a small quantity of unreactedmaterial and the filtrate was then evaporated to dryness. The solid masswhich consisted of the sodium salts of DDT sulfonic acids, and sodiumsulfate was ground to a powder and extracted with 3 portions each of 50ml. of methanol. The filtered extract was then evaporated to dryness.The product consisting of the pure sodium salts of DDT sulionic acids isa light yellow solid which can be ground to a powder.

Fabrics impregnated in accordance with the procedure described inExample #2 were completely protected against damage by the larvae ofmoths or those of the black carpet beetle.

Example #4 20 grams of DDT were dissolved in 30 ml. ofethylenedichloride and 20 grams of chlorosulfonic acid was then added.The mixture was kept at 50 C. for 12 hours and was then cooled at C. for8 hours. The free sulfonic acids of DDT which crystallized out were thenfiltered of! and washed with a small quantity of coldethylenedichloride.

Example 20 grams of DDT were dissolved in 30 ml. of ethylenedichlorideand 20 grams of chlorosulfonic acid was then added. The mixture wasallowed to stand at 50 C. over night. The mass was then poured into 200ml. of water and well agitated. The solvent layer was allowed to settleto the bottom and was then'drawn off and discarded. The aqueous solutionwas then neutralized with caustic soda and was then evaporated todryness. The dry cake was ground to a powder and was then extracted with4 portions of 50 ml. each of absolute ethanol. The combined ethanolextracts were then concentrated to dryness by distilling off thealcohol. The light yellow product was then ground to a powder.

A piece of white cotton fabric weighing 10 grams was soaked in 100 ml.of a 1% aqueous solution of sulfonated castor oil. The fabric was thensqueezed and immersed in 100 ml. of an aqueous bath containing 1 gram ofaluminum sulfate, 2 grams of a 30 Be. solution of sodium bisulfite, 0.5gram of calcium acetate, 1 gram of sodium chloride and 1 gram of sodiumsalts of DDT sulfonic acids as obtained in the above procedure. The bathwas slow-brought to the boiling point and kept boiling for 1 hour. Thefabric was then well rinsed with fresh water and dried.

The piece of treated cotton was then placed into a test jar containingsix cat fleas. All the fleas were dead after three hours.

Having described our invention, what we claim and desire to secure byLetters Patent, is as folows:

A new compound, 1,1,1-trlchloro-2,2-bis(pchlorophenyDethane being atleast once substituted by a sulfonic acid group.

- ERNEST SEGESSEMANN.

NICHOLAS M. MOLNAR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date Re. 22,700 Muller Dec. 4, 19451,707,181 Weiler Mar. 26, 1929 1,887,958 Schwen et al. Nov. 15, 19322,053,610 Hermann et al. Sept. 8, 1936 2,329,074 Muller Sept. 7, 1948.

OTHER REFERENCES Aickin, "Adsorption of Sodium Alkyl Sulfates by Wooland Other Fibers," J. Soc. Dyers 8: C01. 1944, No. 3, PD. 60-65.

Karrer, "Organic Chemistry, 2nd Engl. Ed, 1946, Elsevier Publ. 00., N.Y. (based on 8th Germ.

ed. Leipzig, 1942), pp. 468-469.

